Mitsubishi Lancer Evolution X. Manual - part 523

DIAGNOSIS <TC-SST>

TSB Revision

TWIN CLUTCH- SPORTRONIC SHIFT TRANSMISSION (TC-SST)

22C-49

DTC P0841: Clutch 1 Pressure Sensor System (Poor performance)

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

.

DIAGNOSTIC FUNCTION

TC-SST-ECU checks that the clutch 1 pressure sen-
sor is normal.

.

DESCRIPTIONS OF MONITOR METHODS

The difference between the allowable torque of 
clutch 1 and the engine torque is large.

.

MONITOR EXECUTION

• Continuous

.

MONITOR EXECUTION CONDITIONS 
(OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• P0842: Clutch 1 pressure sensor system (Output 

low range out)

• P0843: Clutch 1 pressure sensor system (Output 

high range out)

• P0753: Shift select solenoid 1 system (Open cir-

cuit)

• P0973: Shift select solenoid 1 system (Short to 

ground)

• P0974: Shift select solenoid 1 system (Short to 

power supply)

• P2733: Clutch/shift switching solenoid 1, spool 

stuck

• P2736: Clutch/shift switching solenoid 1 system 

(Open circuit)

• P2738: Clutch/shift switching solenoid 1 system 

(Short to ground)

• P2739: Clutch/shift switching solenoid 1 system 

(Short to power supply)

• P181B: Clutch 1 (Pressure low range out)
• P181C: Clutch 1 (Pressure high range out)
• P181E: Clutch 2 (Pressure low range out)
• P181F: Clutch 2 (Pressure high range out)
• P185D: Clutch open not possible

Sensor (The sensor below is determined to be 

normal)

• Shift select solenoid 1
• Clutch/shift switching solenoid 1

.

DIAGNOSIS <TC-SST>

TSB Revision

TWIN CLUTCH- SPORTRONIC SHIFT TRANSMISSION (TC-SST)

22C-50

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• Voltage of battery: 8 V or more.
• Voltage of battery: 16.5 V or less.
• Engine speed: 650 r/min or more.
• Time since above engine condition: 1.5 seconds 

or more.

• Engine speed: 6,800 r/min or less.
• Clutch 1 (odd) slip state: Slip or engaged.
• Clutch 1 (odd) slip speed: 20 r/min or more.
• Clutch 2 (even) state: Disengaged.

JUDGMENT CRITERIA

• Calculated torque (Clutch 1 (odd) permit torque − 

engine torque): 200 N⋅ m (148 ft-lb) or more. (4 

seconds)

.

OBD-II DRIVE CYCLE PATTERN

The value of the calculated torque (clutch 1 (odd) 
permit torque − engine torque) remains 200 N⋅ m 

(148 ft-lb) or less for 4 seconds.

.

PROBABLE CAUSES

• Malfunction of TC-SST-ECU
• Malfunction of clutch 1 pressure sensor
• Malfunction of clutch assembly
• Malfunction of engine system
• Insufficient fluid 

DIAGNOSTIC PROCEDURE

Required Special Tools:

• MB991958 Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827 M.U.T.-III USB Cable
• MB991910 M.U.T.-III Main Harness A

AC710619

START

No

Yes

Yes

Good

Malfunction

END

Vehicle condition met

No

Continuous failure for 2 sec

No

Yes

|Calculated torque| > 200 N·m (148 ft-lb)

AB

4

DIAGNOSIS <TC-SST>

TSB Revision

TWIN CLUTCH- SPORTRONIC SHIFT TRANSMISSION (TC-SST)

22C-51

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C − 

Troubleshooting 

P.54C-15

.) After repairing the CAN 

bus line, go to Step 2.

STEP 2. Scan tool diagnostic trouble code
Check the engine diagnostic trouble code. (Refer to GROUP 
13A − Troubleshooting 

P.13A-48

.)

Q: Is the DTC set?

YES : Perform the relevant troubleshooting.
NO :  Go to Step 3.

STEP 3. Fluid check
Drain the fluid and check that no bubbles, foreign material and 
contamination are found.
Q: Is the check result normal?

YES : Go to Step 4.
NO :  Replace the fluid.

STEP 4. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Gradually accelerate the vehicle.
(3) Accelerate the vehicle with the accelerator pedal fully 

opened.

(4) Check that the DTC is reset.
Q: Is DTC No.P0841 set?

YES : Replace the clutch assembly. (Refer to GROUP 22D 

−Transaxle 

P.22D-6

.)

NO :  Intermittent malfunction. (Refer to GROUP 00 − How 

to Cope with Intermittent Malfunction 

P.00-15

.)

DTC P0842: Clutch 1 Pressure Sensor System (Output low range out)

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

.

DIAGNOSTIC FUNCTION

TC-SST-ECU checks that the clutch 1 pressure sen-
sor is normal.

.

DESCRIPTIONS OF MONITOR METHODS

The output of the clutch 1 pressure sensor is too low.

.

MONITOR EXECUTION

• Continuous

.

MONITOR EXECUTION CONDITIONS 
(OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• P0841: Clutch 1 pressure sensor system (Poor 

performance)

DIAGNOSIS <TC-SST>

TSB Revision

TWIN CLUTCH- SPORTRONIC SHIFT TRANSMISSION (TC-SST)

22C-52

• P0843: Clutch 1 pressure sensor system (Output 

high range out)

• P0753: Shift select solenoid 1 system (Open cir-

cuit)

• P0973: Shift select solenoid 1 system (Short to 

ground)

• P0974: Shift select solenoid 1 system (Short to 

power supply)

• P2733: Clutch/shift switching solenoid 1, spool 

stuck

• P2736: Clutch/shift switching solenoid 1 system 

(Open circuit)

• P2738: Clutch/shift switching solenoid 1 system 

(Short to ground)

• P2739: Clutch/shift switching solenoid 1 system 

(Short to power supply)

• P181B: Clutch 1 (Pressure low range out)
• P181C: Clutch 1 (Pressure high range out)
• P181E: Clutch 2 (Pressure low range out)
• P181F: Clutch 2 (Pressure high range out)
• P185D: Clutch open not possible

Sensor (The sensor below is determined to be 

normal)

• Shift select solenoid 1
• Clutch/shift switching solenoid 1

.

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• Voltage of battery: 8 V or more.
• Voltage of battery: 16.5 V or less.

JUDGMENT CRITERIA

• Sensor voltage: 1.16 V or less. (160 millisecond)

.

OBD-II DRIVE CYCLE PATTERN

The voltage of the clutch 1 pressure sensor remains 
1.16 V or more for 160 milliseconds.

.

PROBABLE CAUSES

• Malfunction of TC-SST-ECU
• Malfunction of clutch 1 pressure sensor

AC710620

START

No

Yes

Yes

Good

Malfunction

END

Monitoring condition met

No

Continuous failure
for 160 msec

No

Yes

Sensor voltage
< threshold value